Reasoning. ReligionEthical HealthEnvironmental . Types of Vegetarians. Lacto-ovo vegetarians do not eat red meat, fish, or poultry, but they do eat eggs and dairy products;Lacto-vegetarians consume dairy, but not eggs or any meat productsVegans consume no meat, eggs or dairy, and eat only plant-based products. Semi/Demi-vegetarians: Eat fish and/or chicken but no red meat. .